The invention concerns a method for utilizing the pressure- and/or temperature conditions prevailing in deep waters, particularly in the sea for the production of energy as well as a device for carrying out this method.
As known, there is an urgent need for non-polluting methods for obtaining energy, which permit the utilization of natural forces without using up basic substances, particularly fuels, which exist naturally on the earth in limited quantities only, and which cannot be justified in the long run either from an economical viewpoint or in view of the resulting environment pollution and ecological changes.
The object of the invention is thus to provide a possible non-polluting method for obtaining energy in a reversible and reproducible manner from existing natural forces without the use and consumption of valuable raw materials.
The invention is based on the finding that the physical conditions in the depth of waters, particularly the constant pressure and/or temperature conditions prevailing there, which as known, differ considerably from the physical conditions outside these waters, can be used with advantage for generating energy based on differences of these conditions.
So-called heat pumps, which can utilize the differences of the temperature conditions for the production of energy, already belong to the state of the art.
The method according to the invention, on the other hand, comprises the following steps:
A tank whose contents can be influenced by the respective outside pressure and/or by the respective outside temperature, and which contains a medium varying its physical state, particularly its state of aggregation and/or its volume, under the action of pressure and/or temperature is lowered into a depth of the water in which the pressure- and/or temperature conditions are substantially different from the atmosphere outside the water, which cause the medium, preferably by varying its state of aggregation, to rise in a connecting pipe leading to a preferably identical tank arranged on the surface outside the water, in which the energy of flow of the rising medium is utilized preferably by mechanical means.
In this method, the medium is not used up, and can be readily used again and remains fully available for a repetition of the steps in the opposite direction of flow. Only the considerable differences in the pressure- and/or temperature conditions inside and outside the water are used for the production of energy.
In contrast to the known heat pumps used for generating energy, no pumping power is required in the method according to the invention.
Preferably a medium is used in the subject of the invention whose specific gravity in the liquid state is greater than 1, so that the tank filled with the condensed medium can sink readily to the desired depth without any auxiliary means.
In order to ensure the desired course of the method of the invention, it is advisable to keep the tank in the desired nominal depth to the end of utilizable upward flow, e.g. by means of remote-controlled holding elements.
The method according to the invention is reversible and can be repeated resp. in the opposite direction insofar as a tank, used as a collecting tank, can be lowered to the desired depth, after it has been filled with the condensed, liquefied medium, to be used in the depth as a starting tank, with the gaseous medium traversing the connecting pipe in the opposite direction. It is advisable to use tanks which float in the empty state, which rise by themselves to the water surface, after the gaseous medium has been removed and the tank has been detached from a mount in the depth of the water, but which sinks automatically to the nominal depth when filled with a specifically heavier medium.
The medium contained in the respective starting tank is preferably under an excess pressure before it is lowered in order to change its state of aggregation, for example, for liquefaction, which pressure conditions or the changes of the physical properties necessary for the medium to rise in the connecting pipe.
According to another very essential feature of the invention the medium is deposited in its respective flow path in condenser behind the energy converter, e.g. a turbine. This way no backpressure can be formed in the vapor circuit according to the invention, which could hinder or stop the course of the method. It is desirable if the condensation pressure behind the energy converter is at least substantially identical with the atmospheric pressure, otherwise elaborate chambers would have to be provided.
The steam should be superheated in its path to the energy converter to such an extent that the turbine, etc. which is used as such a converter, does not work in the wet steam range; the condensed particles of the medium would reduce as droplets the output of the energy converter and would cause considerable wear of the energy converter.
The density of the condensate should be as high as possible, compared to that of water, so that the tank to which the medium is fed in the boiling state actually is made to sink rapidly. According to another feature of the invention, the following substances are suitable as media: chlorine, hydrogen iodide, methane difluoride, ethylene trifluoride, also octofluorcyclobutane, if necessary. Propane would meet the required conditions regarding pressure and temperature even better, but it has a too low density of about 525 kg/cu m. Octofluorclobutane is particularly suitable insofar as the expansion of the saturated steam does not take place in the wet steam range. The greatest mechanical performance can be expected when working with superheated methane difluoride vapor.
The invention also relates to devices for carrying out the above described methods.
Such a device is substantially characterized by a first floating tank which can be filled with a liquid or gaseous medium and closed by a valve, by a preferably identical tank, which can likewise be closed by such a valve, as well as by a connecting pipe in which is arranged an energy converter for utilizing the flow of the medium from one tank to the other for the production of energy.
In the connecting pipe is arranged at least one condenser, and preferably also at least one superheater.
The specific volume and the space requirement of the medium are considerably increased by the evaporation, under certain circumstances a thousand times. If no volume change is permitted, the pressure in the tank can increase to such an extent that no evaporation takes place and would have to be stopped after the tank has been lowered. It is therefore advisable to change the size of the tank and its volume resp. in the course of the method and to regulate it optimally in such a way that the required optimum pressure conditions are obtained in the tank. This can be achieved, for example, in this way that the degree of filling of the tank is varied or that the capacity of the tank is limited upward, for example, by designing the tank as a sylphon or in telescope fashion.
On the one hand, the tank should be readily insulatable to prevent evaporation of the medium during the sinking on the other hand, however they should ensure a good heat transfer in the lowered state. Within the framework of the invention it is possible to provide either an insulation which meets the two conditions satisfactorily on the average, or to provide variation of the insulating effect of the tank walls, which leads to a corresponding result. Such an insulation, which is variable in its intensity, can be achieved in various ways on the basis of the state of the art, for example, by using a tank shell whose filling is variable or which encloses the tank only in phases, e.g. which forms a shaft in certain regions in the path of the tank in which the tank is raised or lowered, or a bell which sinks together with the tank and which releases it only in the lowest position. After the tank has been lowered, a good preferably rapid heat transfer should be provided in any case.